Trieces irwini, Ranjith & Priyadarsanan, 2022

Ranjith, A. P. & Priyadarsanan, Dharma Rajan, 2022, First description of the metopiine genus Trieces Townes, 1946 (Hymenoptera: Ichneumonidae) from the Indomalayan region with three new species from India, European Journal of Taxonomy 794 (1), pp. 1-17 : 5-8

Trieces irwini sp. nov.

urn:lsid:zoobank.org:act:83D7FCCF-F4E7-41A0-B684-70D0F3AB89E9

Figs 1–2

Differential diagnosis

The new species, Trieces irwini sp. nov. differs from the other species of the onitis group in having the following combination of characters: i) mandible has only upper tooth, ii) first metasomal tergite with ventro-lateral carina. This new species is more or less similar to T. homonae in having yellow face, but differs from the latter based on the following characters: mesopleuron with distinct longitudinal wrinkles posteriorly (vs without longitudinal wrinkles posteriorly in T. homonae ), propodeum sparsely setose (vs densely setose in T. homonae ), scutellum sparsely setose (vs densely setose in T. homonae ), epicnemial carina joining with subtegular ridge (vs not joining with subtegular ridge in T. homonae ).

Etymology

This species is named after veteran dipterologist Prof. Michael Edward Irwin (emeritus professor, University of Illinois, Urbana-Champaign, USA), who is a well-wisher and supporter of ATREE Insect taxonomy and Conservation Laboratory.

Material examined

Holotype INDIA • ♀; Karnataka, Chamarajanagar, Biligiri Ranga Biligiri Rangaswamy Temple Tiger Reserve, Vellachy Metty ; 14–30 Sep. 2005; Malaise trap; D.R. Priyadarsanan leg.; AIMB.

Paratype INDIA • 1 ♂; Karnataka, Chamarajanagar, Biligiri Ranga Hill Wild Life Sanctuary, Gombekallu ; 11°54.363′ N, 77°11.235′ E; 17Aug.–21 Sep. 2006; Malaise trap; D.R. Priyadarsanan leg.; AIMB .

Description

Female

MEASUREMENTS. Body length 5.5 mm, length of fore wing 3.4 mm.

HEAD. Head transverse in dorsal view, not narrowed posteriorly behind eyes, 1.8 × as wide as long medially; frons smooth, setose; occiput smooth, glabrous medially rest setose; temple smooth dorsally, not convex, length 0.6 × as long as transverse diameter of eye in lateral view. Occipital carina present. Eyes sparsely setose. Distance from lateral ocellus to eye equal to diameter of ocellus. Distance between lateral ocellus 2.0× distance from lateral ocellus to eye. Face not convex in lateral view, 1.4× as wide as long in anterior view, slightly narrowed posteriorly, smooth, setose. Clypeus separated from face by shallow depression, sculptured similar to face, with lower margin weakly convex in middle. Length of malar space equal to basal width of mandible. Mandible with only upper tooth. Antennae with 19 flagellomeres; all flagellomeres longer than wide; first flagellomere 1.6 × as long as maximum width, 1.2× as long as second flagellomere.

MESOSOMA. Mesosoma 1.6× as long as high; mesonotum densely, distantly punctate, interspace smooth, without notauli. Scutellum smooth, sparsely punctate with distinct lateral carina. Mesopleuron punctate with longitudinal wrinkles posteriorly, sparsely setose. Epicnemial carina distinct, reaching anterior margin of mesopleuron. Propodeum sparsely punctate anteriorly rest smooth with parallel longitudinal dorsal carinae; spiracles small, elliptical, separated from pleural carina. Metapleuron smooth, setose anteriorly rest glabrous, with distinct longitudinal slit and several short longitudinal rugae ventrally. Fore wing 3.7× as long as wide. Vein 1cu-a weakly postfurcal. Hind femur 2.4 × as long as its maximum width in lateral view. Hind tibia 3.0 × as long as its maximum width. Ratio of length of hind tarsomeres 1–5, 3: 1.4: 1: 1: 1.6.

METASOMA. Metasoma coarsely and densely punctate. First metasomal tergite 1.1 × as long as apical width, with distinct dorso-lateral, ventro-lateral and pair of mid longitudinal carinae. Second metasomal tergite 0.7 × as long as its apical width, with distinct dorso-lateral carina and midlongitudinal carinae. Third metasomal tergite 0.7× as long as its apical width, with dorso-lateral and midlongitudinal carinae distinct in basal half.

COLOR. Body mostly black; antennae, face, lateral temples posterior half, maxillary and labial palps, fore and mid legs, hind coxae apically, metasomal sternites and ovipositor sheath yellow to yellowish brown, hind tibiae, tarsi reddish brown.

Male

Same as female.

Distribution

India (Karnataka).

Biology

Unknown.

Figures

Fig. 1. Trieces irwini sp. nov., holotype, ♀ (AIMB). A. Habitus, lateral view. B. Head, anterior view. C. Head, dorsal view. D. Head, ventral view. E. Head and mesosoma, lateral view. F. Mesosoma, dorsal view.

Fig. 2. Trieces irwini sp. nov., holotype, ♀ (AIMB). A. Propodeum, dorsal view. B. Fore wing. C. Metasoma, lateral view. D. Metasoma, dorsal view.